Several people at an immigration detention center in a Mexican city on the US border died in a fire that broke out at the facility overnight, local media reported on Tuesday.

An AFP journalist saw firemen and rescuers placing several bodies covered with blankets in the parking lot of the National Migration Institute (INM) facility in Ciudad Juarez.

INM press personnel reached by AFP confirmed the fire, but declined to specify the number of victims.

Local media, citing unnamed sources, estimated that there were dozens of deaths.

A rescuer who asked not to be identified because he was not authorized to speak to the press explained that there were about 70 migrants, mostly Venezuelans, at the site.

The fire broke out shortly before midnight, prompting the mobilization of firefighters and dozens of ambulances.

Ciudad Juarez, which neighbors El Paso, Texas, is one of the border towns where numerous undocumented migrants seeking refuge in the United States remain stranded.

A recent report by the International Organization for Migration (IOM) states that since 2014, some 7,661 migrants have died or disappeared en route to the United States, while 988 perished in accidents or while traveling in subhuman conditions.